1. Field of the Invention
The present invention relates generally to pressure regulators and, more particularly to, a pressure regulator including a diaphragm.
2. Description of the Related Art
Pressure regulators are configured to produce a desired output pressure of a fluid from an input pressure of the fluid. Often, pressure regulators are configured to reduce the input pressure so that the output pressure is substantially less than the input pressure.
Single stage and dual stage pressure regulators are available to reduce the input pressure. Single stage regulators are often employed to regulate fluid pressure in gas appliances such as gas grills. Dual stage pressure regulators are often employed for regulating fluid pressure of natural gas or propane in domestic fluid systems. For instance, one dual stage pressure regulator has a first stage that reduces the fluid pressure from a storage tank, such as a propane storage tank, to around 10 psi, while a second stage reduces the 10 psi input to around 11 inches water column output pressure. Some regulations require the output pressure not to exceed 2 psi.
Typically, pressure regulators include a housing formed of upper and lower housing portions that are connected together with fasteners and a diaphragm located between the upper and lower housing portions. An outer periphery of the diaphragm often has a lip shaped to fit inside an annular recess in the lower housing portion to help seal between the upper and lower housing portions. However, such lips are subject to leakage. Thus, there is a need in the art for improved sealing between upper and lower housing portions of a pressure regulator.
Generally, the diaphragm of the pressure regulator is shaped to have an inner annular section configured to raise and lower during operation of the pressure regulator. The diaphragm has a flexible connecting section radially extending between the inner annular section and the outer lip. The flexible connecting section has a thickness less than a thickness of the inner annular section and the lip. A diaphragm plate is positioned on top of the inner annular section to provide additional rigidity to the inner annular section as the inner annular section raises and lowers during operation. In some commercial products, the diaphragm plate is loosely located on the inner annular section, which can result in shifting of the diaphragm plate with respect to the inner annular section and potentially cause problems with operation. In other commercial products, the diaphragm plate is insert-molded into the diaphragm to prevent shifting of the diaphragm plate, but this process can be expensive. Thus, there remains a need in the art for a pressure regulator with an improved diaphragm plate that prevents shifting relative to the diaphragm without requiring insert-molding.
In some conventional pressure regulators, projections on the lower housing portion suspend a bottom surface of the inner annular section of the diaphragm above an inner surface of the lower housing portion to reduce contact between the bottom surface and the lower housing portion. However, there still remains some contact between the bottom surface and the projections, which can result in damage to the diaphragm prior to operation. Thus, there is a need in the art for a diaphragm of a pressure regulator in which the bottom surface is completely suspended in the housing without contacting any portions of the housing.
Generally, the pressure regulator includes a valve body disposed in the lower housing portion and is slidable among a plurality of operational positions. Typically, a valve disc is retained by the valve body. The valve disc is configured to engage a valve seat surrounding a fluid passageway when the valve body is in a closed position. When the valve disc and valve body are spaced from the valve seat, fluid passes through the passageway into a pressure chamber of the lower housing portion. A lever operatively couples the diaphragm with the valve body. When the input pressure pushes the valve disc and valve body away from the valve seat to allow fluid to pass through the passageway, pressure in the pressure chamber increases, and the diaphragm rises. As the diaphragm rises, the lever pivots about a pivot point and urges the valve body and valve disc back toward the valve seat. This reduces the amount of fluid that passes through the passageway and reduces the pressure in the pressure chamber. This back and forth action results in pressure regulation by regulating fluid flow through the passageway, around the valve body, and into the pressure chamber. When the fluid flows around the valve body, the valve body tends to vibrate or hum. Thus, there is a need in the art to reduce such vibrations or humming